docs: def get_fieldsets(self, request, obj=None):
          """
          Slightly different fields are shown for Add and Change:
           - default_alternative can only be changed
           - name can only be set on Add
          """
          main_fields = ('description', 'start_date', 'end_date', 'state')
  
          if obj:
              main_fields += ('default_alternative',)
          else:
              main_fields = ('name',) + main_fields
  
          return (
              (None, {
                  'fields': main_fields,
              }),
              ('Relevant Goals', {
                  'classes': ('collapse', 'hidden-relevant-goals'),
                  'fields': ('relevant_chi2_goals', 'relevant_mwu_goals'),
              })
          )